Safety device for pump-governors.



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WITNESSES SAFETY DEVICE FOR PUMPGOVERNORS.

'Specification of Letters Patent.

Application led October 9, 1912. Serial No. 724,708.

To all whom it may concern:

Be it known that I, 191111.11 l L. Cnri'rl-:N- DEN, a citizen of theUnited'States, residing 'at Edgewood, in the county of Allegheny andState of Pennsylvania, have invented new and useful Improvements inSafety Devices for Pump-Governors, of which the following is aspecification.

This invention relates to pump governors forgmotor driven v'fluidcompressors, and

. more particularly to a safety or protection device adapted to heemployed in connection therewith.

It has heretofore been customary to provide some form of unloading orstarting device in connection with the governor of a' motor driven fluidcompressor so that'in starting, the motor can attain its normal speedwithout undue load.l It occasionally happens, however, that currentgives out temporarily and if the pump governor should happen to be inthe cut-in position at that time, the parts will remain in said positionand then when the current comes on again, the unloading device will beineffective to prevent undue load on the motor.

The principal object of v provide means for automatically causing thepump governor to shift to the cut-out osition upon failure of current,so thatv when current is again supplied, the starting or unloadingdevice will bein the position to pass through the necessary cycle forpreventing an undue starting torque or excessive load on the motor.

In the accompanying drawing; Figure 1 is a sectional view of an electricpump governor with my improvement applied thereto and Fig. 2 adiagrammatic view of a motor driven fluid compressor equipment showingmy invention embodied therein.

In order to illustrate one form of my invention, an electric pumpgovernor 1 of a well tacts 3 adapted to engage with stationary switchcontacts 4 for closing the `circuit which supplies current to theelectric motor of the air compressor 8. A main valve mechanism.cmprising a valve 5 and pistons 6 -and 7 controls the admission andrelease of fluid under pressure to and from the switch piston 2.

my invention is tov parts of the A low tension regulating devicecomprislng a dlaphragm 9 subject on one side to pressure through passage10 controls a va ve 11 adapted to govern the release of the piston 7 andI regulating device comprising a dlaphraglm 12 subject on one side topump pressure t rough the passage 13 controls a valve 14 for i 6. Apassage 15 su plies fluid at pump pressure to valve chamer 16 andpistons 6 and 7 being loosely fitted, fiuid equalizes on opposite sidesof said pistons.

When the ump pressure is less than the adjusted tenslon of spring 17,the 9 opens valve l1 andvents fluid from the piston 7, causing the toassume the position shown in Fig. 1, in which a cavity 18 connects port19 leading to switch piston 2 with an exhaust port 20, so that piston 2is pressed vto its inner positionby spring 21, closing the switch andthe pump circuit. Upon a rise in pump pressure to exceed that of spring22, the valve 14 is opened, valve 11 having been previously closed bythe rise in pump pressure acting on diaphragm 9. Fluid is thereuponvented from piston 6, while fluid under pressure has equalized aroundpistonl 7 and the main valve mechanism is shifted to its oppositeposition, 4in which'passage 19 is opened to valve chamber 16, so thatfluid under ressure is admitted to piston 2, thereby shi ting Same toits outer position, breaking the pump motor circuit.

Any type of unloading device may be employed, the form shown in thedrawing being circuit in starting the starting device 23 having a pistona piston 25, subject the motor. As shown, may comprise a casing chamber24 containing on one side to the pressure of a spring 26 and having itsopposite side connected by a pipe. 27 to a 28'leading to the seat Uponmovement of the main valve mechanism to the cut-in position, as shown inFig. 1, a restricted port 31 in the valve 5 registers with port 28, sothat fluid is gradually sup- Patented Nov. 3, 1914.

piieri rrom valve cnainoer 16 to the piston chamber 24. By ment of thepiston is etlected and thereby the drum 29 is rotated to gradually cutout resistance in the motor circuit.

According-to my improvement, means are provided t'or automaticallyeecting the movement of the electric pump governor to its cut outposition upon ailure oit current in the line circuit and for thispurpose l preterahly employ a valve 32 controlled by a magnet 33,connected across the line circuit, as shown in Fig. 2, for venting fluidfrom tlie piston 6 of the main valve mechanism of the governor.

rlhe valve 32 the energizatilon of the magnet is normally held closed bythe current fails, the valve 32 opens and fluid 'is vented from piston adrop in punp i 6 through pipe 34 to exhaust porty 35. By this means, ifthe pump governor should happen to be in its cut-in position when thecurrent `i'iiils, the operation of the magnet controlled valve 32automatically etlects the shifting o the governor parts to the cut-outpositioinso that when the current again comes on, the governor will bein the ciit-out position and when the governor subsequently moves tocut-.in position, due to pressure, it will be evident `that the unloa orstarting device will be ready to operate in the usual manner to preventlan undue starting load on the pump motor.

lt will be understood nient may be employed in connection with varioustypes of starting devices, such as the torni in which. an automaticvalve device operates to relieve the iiuid pressure on the pump pistonat starting, a variable resistance. adapted to be gradually cut out ofthe uiotorcircuit as the speed increases, or in connection withalternating current on single phase motors where various employed themotor.

Having now that my improvethis means a gradual movey current to theactuating piston 33, but when devices are to reduce the starting torqueof described iny invention. what l miseri l claim as new and desire tosecure by Letters Patent, is zl. The combination with an electric motordriven pump for compressing huid and a governor controlled by variationsin pump pressure for opening and closing the pump motor circuit, of amagnet controlled by current supplied from the source which supplies umpmotor circuit and a valve controlled y said magnet and adapted uponfailure of current to open and vent fluid from said governor to sliitsame to its cut-out position.

2. The combination with an electric plump overnor comprising an electricswitc an therefor, and a valve mechanism operated according tovariations in punippressure for controlling the fluid said actuating.piston, of an electro-macnetically controlled valve opero ated uponfailure ot current for venting duid from said valve mechanism to therebyelectric switch cliect tlie movement of said to the cut-out position.

rlhe combination with an electric plump overnor comprising an electricswitc or controlling the pump motor circuit, an actuating pistontherefor, a valve for controlling the fluid pressure on said piston, anda movable abutment operated by yenting fluid from one side thereof foractuating said valve to vary the duid pressure on said piston to therebyshift the switch to cut-out position, ot a magnet normally energized by1 current supplied trom the sourcewhich supplies current to the pumpmotor circuit and a valve controlled by said magnet and adapted uponfailure of current to vent fluid from said abutment.

"in testimony my hand.

whereof l have hereunto set Pliliill) L. Gill'l'lllNDEl'.

Witnesses A. M. Gniiiiinn'rs, lV. W'. Maurin.

